diff options
Diffstat (limited to 'srcs/juloo.keyboard2/ListGroupPreference.java')
| -rw-r--r-- | srcs/juloo.keyboard2/ListGroupPreference.java | 83 |
1 files changed, 53 insertions, 30 deletions
diff --git a/srcs/juloo.keyboard2/ListGroupPreference.java b/srcs/juloo.keyboard2/ListGroupPreference.java index 5631aed..9136a0c 100644 --- a/srcs/juloo.keyboard2/ListGroupPreference.java +++ b/srcs/juloo.keyboard2/ListGroupPreference.java @@ -15,10 +15,10 @@ import org.json.JSONException; /** A list of preferences where the users can add items to the end and modify and remove items. Backed by a string list. Implement user selection in [select()]. */ -public abstract class ListGroupPreference extends PreferenceGroup +public abstract class ListGroupPreference<E> extends PreferenceGroup { boolean _attached = false; - List<String> _values; + List<E> _values; /** The "add" button currently displayed. */ AddButton _add_button = null; @@ -27,16 +27,13 @@ public abstract class ListGroupPreference extends PreferenceGroup super(context, attrs); setOrderingAsAdded(true); setLayoutResource(R.layout.pref_listgroup_group); - _values = new ArrayList<String>(); + _values = new ArrayList<E>(); } /** Overrideable */ /** The label to display on the item for a given value. */ - String label_of_value(String value, int i) - { - return value; - } + abstract String label_of_value(E value, int i); /** Called every time the list changes and allows to change the "Add" button appearance. @@ -58,29 +55,34 @@ public abstract class ListGroupPreference extends PreferenceGroup /** Called when an item is added or modified. Returns [null] to cancel the action. */ - abstract void select(SelectionCallback callback); + abstract void select(SelectionCallback<E> callback); + + /** A separate class is used as the same serializer must be used in the + static context. See [Serializer] below. */ + abstract Serializer<E> get_serializer(); /** Load/save utils */ /** Read a value saved by preference from a [SharedPreferences] object. + [serializer] must be the same that is returned by [get_serializer()]. Returns [null] on error. */ - static List<String> load_from_preferences(String key, - SharedPreferences prefs, List<String> def) + static <E> List<E> load_from_preferences(String key, + SharedPreferences prefs, List<E> def, Serializer<E> serializer) { String s = prefs.getString(key, null); - return (s != null) ? load_from_string(s) : def; + return (s != null) ? load_from_string(s, serializer) : def; } /** Decode a list of string previously encoded with [save_to_string]. Returns [null] on error. */ - static List<String> load_from_string(String inp) + static <E> List<E> load_from_string(String inp, Serializer<E> serializer) { try { - List<String> l = new ArrayList<String>(); + List<E> l = new ArrayList<E>(); JSONArray arr = new JSONArray(inp); for (int i = 0; i < arr.length(); i++) - l.add(arr.getString(i)); + l.add(serializer.load_item(arr.get(i))); return l; } catch (JSONException e) @@ -91,29 +93,32 @@ public abstract class ListGroupPreference extends PreferenceGroup /** Encode a list of string so it can be passed to [Preference.persistString()]. Decode with [load_from_string]. */ - static String save_to_string(List<String> l) + static <E> String save_to_string(List<E> items, Serializer<E> serializer) { - return (new JSONArray(l)).toString(); + List<Object> serialized_items = new ArrayList<Object>(); + for (E it : items) + serialized_items.add(serializer.save_item(it)); + return (new JSONArray(serialized_items)).toString(); } /** Protected API */ /** Set the values. If [persist] is [true], persist into the store. */ - void set_values(List<String> vs, boolean persist) + void set_values(List<E> vs, boolean persist) { _values = vs; reattach(); if (persist) - persistString(save_to_string(vs)); + persistString(save_to_string(vs, get_serializer())); } - void add_item(String v) + void add_item(E v) { _values.add(v); set_values(_values, true); } - void change_item(int i, String v) + void change_item(int i, E v) { _values.set(i, v); set_values(_values, true); @@ -133,7 +138,7 @@ public abstract class ListGroupPreference extends PreferenceGroup String input = (restoreValue) ? getPersistedString(null) : (String)defaultValue; if (input != null) { - List<String> values = load_from_string(input); + List<E> values = load_from_string(input, get_serializer()); if (values != null) set_values(values, false); } @@ -156,7 +161,7 @@ public abstract class ListGroupPreference extends PreferenceGroup removeAll(); boolean allow_remove_item = should_allow_remove_item(); int i = 0; - for (String v : _values) + for (E v : _values) { addPreference(this.new Item(getContext(), i, v, allow_remove_item)); i++; @@ -168,10 +173,10 @@ public abstract class ListGroupPreference extends PreferenceGroup class Item extends Preference { - final String _value; + final E _value; final int _index; - public Item(Context ctx, int index, String value, boolean allow_remove) + public Item(Context ctx, int index, E value, boolean allow_remove) { super(ctx); _value = value; @@ -185,8 +190,8 @@ public abstract class ListGroupPreference extends PreferenceGroup @Override protected void onClick() { - select(new SelectionCallback() { - public void select(String value) + select(new SelectionCallback<E>() { + public void select(E value) { change_item(_index, value); } @@ -222,8 +227,8 @@ public abstract class ListGroupPreference extends PreferenceGroup @Override protected void onClick() { - select(new SelectionCallback() { - public void select(String value) + select(new SelectionCallback<E>() { + public void select(E value) { add_item(value); } @@ -231,8 +236,26 @@ public abstract class ListGroupPreference extends PreferenceGroup } } - public interface SelectionCallback + public interface SelectionCallback<E> + { + public void select(E value); + } + + /** Methods for serializing and deserializing abstract items. + [StringSerializer] is an implementation. */ + public interface Serializer<E> + { + /** [obj] is an object returned by [save_item()]. */ + E load_item(Object obj); + + /** Serialize an item into JSON. Might return an object that can be inserted + in a [JSONArray]. */ + Object save_item(E v); + } + + public static class StringSerializer implements Serializer<String> { - public void select(String value); + public String load_item(Object obj) { return (String)obj; } + public Object save_item(String v) { return v; } } } |